Self starting synchronized motor



Feb. 26, 1935. TQEWE Re. 19,481

SELF STARTING SYNCHRONI ZED MOTOR DRTVE MEANS FOR CLOCKS Original FiledAug. .2, 1929 INVENTOR FI'LZZ 2"0 ewe,

,' ATTORNEY Reissued Feb. 26, 1935 SELF STARTING SYNCHRONIZED MOTORDRIVE MEANS FOR CLOCKS Fritz Toewe, Villingen, Germany, assiguor, bymesne assignments, to Kienzle Taxameter und Apparate A. vG. Villingcn,Germany, a corporation of Germany Original No. 1,788,812, dated January13, 1931, Serial No. 382,882, August 2, 1929. Application for reissueMay'2, 1931, Serial No. 534,682. In Germany December 9, 1928 29 Claims.

This invention relates to improvements in a synchronous motor fordriving clocks and the like, and it consists in the novel features,which. are hereinafter described.

One of theobjects of myinvention is to make a synchronous motor selfstarting.

Another object of my invention is to produce a more perfect synchronousmotor than is at present in use.

A further object of my invention is to facilitate the starting andthesynchronization or falling into step of the component parts of my motor.

A still other object of my invention is to have my improved synchronousmotor simple, durable and inexpensive.

Other objects and advantages will hereinafter appear.

I attain these objects in one embodiment of my invention by employing arapidly revolving Ferraris rotating field, from which is branched off amulti-polar alternating field for a synchronous motor of slower rotaryspeed.

In order to facilitate the starting and falling into step of thesynchronous rotor when operating together with the asynchronous rotor,both rotors are coupled by means of a flexible connection.

The details of the abo e form of my invention are illustrated in theaccompanying drawing; and the objects of my invention may also beattained by any mechanical equivalent or obvious modification of thesame.

In the drawing,

Fig. 1 is a front elevation of my synchronous motor; and

Fig. 2 is a section on the line'A-B of Fig. 1.

Like numerals refer to like parts throughout the two views:

1 designates the stator and 2 the exciter winding, which togetherconstitute the field of my synchronous motor.

The pole pieces 3 and 4 are split and each half is provided with ashielding coil 5, thereby producing a Ferraris rotating field with onepair of poles. A short-circuit rotor 6, of a construction known to theprior art and consisting of a copper cage15 with laminated soft-ironcore 16, is movably disposed in this rotating field.

To each of the two legs of the stator 1 is secured a pole piece 7, 8with intermediate supports 9, 9 made of magnetically conducting materialwith the result that a rotating field for the synchronous rotor 10, madeof magnetic steel, is produced between the poles of the polepieces 7 and8 as an auxiliary field for the synchronous motor.

In the example shown, the alternating field of the synchronous motor isdivided for a 6-pole rotor; however, on both sides of the vertical planeof symmetry one pole of each is eliminated; so that there exist on eachside two poles only of the same sign, N, N or S, S. Hence, these polesare disposed in the correct pole distribution of a 6-pole field.

The synchronous rotor 10 is rotatably disposed on the axle 11 of theasynchronous rotor 6 by means of a bearing box 12 and is coupled withthe asynchronous rotor 6 by means of a helical spring 13, which isattached on the one side to a bearing box 12 and, on the other side, toan adjusting collar 14, which is clamped onto shaft 11.

It is evident that the Ferraris rotating field with the one pair ofpoles 3 and 4 revolves more rapidly than the 6-pole synchronous rotor10. The fiexible coupling between the two rotors 6 and 10 serves toallow the asynchronous rotor'6, whose starting torsional moment, in caseof a rigid connection with the synchronous rotor 10, would not besufiicient to force the latter out of its rest position, to accumulatefirst enough force, with a simultaneous imparting of a tension to spring13, to force the synchronous rotor out of its position of rest and keepit moving. Inasmuch as the asynchronous rotor 6, for instance whenopcrating with a. c. of periods, has the tendency to reach a rotaryspeed of 3000 R. P. M., it rapidly imparts to the synchronous rotor 10,whose synchronous rotary speed is 1000, this number of revolutions. Assoon as the synchronous rotor has fallen in step, it takes the lead withrespect to the asynchronous motor; from this moment on,

the spring 13 acts in the opposite direction upon the asynchronousarmature in the manner that the latter is forced to maintain the rotaryspeed of the synchronous motor.

If 'a decrease of the rotary speed of the synchronous rotor is notdesired, the alternating 'field of the synchronous motor, and,accordingly,

of its rotor, may, of course, be provided with one pair of poles only.

Variations are possible, and parts of my invention may be used withoutother parts.

I do not, therefore, restrict myself to the details as shown in thedrawing but I intend to include also all mechanical equivalents andobvious modifications of the; same within the scope of my invention.

What I claim as new is:

1. In a self starting synchronous motor for driving clocks and the like,in combination, an

Ferraris rotating field, and a synchronous rotor having a multi-polaralternating field branched oil from said Ferraris rotating field; saidrotors being interconnected by flexible means.

2. In a self starting synchronous motor for driving clocks and the like,incombination, an asynchronous rotor having a rapidly revoluble Ferrarisrotating field, and a synchronous motor of slower rotational speedhaving a multl-polar alternating field branched 011 from said Ferrarisrotating field, the shafts of said rotors being yieldingly coupled.

3. In a self starting synchronous motor for driving clocks and the like,in combination, an asynchronous rotor having a high speed Ferrarisrotating field, a magnetic steel synchronous rotor having an alternatingfield, said alternating field including opposite pole pieces, said polepieces being connected magnetically with the stator of said Ferrarisrotating field, and a yielding coupling between the supports of saidrotors.

4. A device of the class described, an asynchronous rotor having a highspeed Ferraris rotating field, a synchronous rotor of magnetic material,pole pieces arranged at opposite sides of said rotor, said pole piecesbeing magnetically connected to the stator of said Ferraris field andyielding means tor coupling the supports of said rotors.

5. In combination, a magnet having exciting means and pole piecesproducing a rotary field and an alternating field; a single windingexciting said pole pieces; rotors influenced to rotate by said fieldsrespectively; and means whereby the rotor in the rotating field startsthe other rotor.

6. In combination a magnet having exciting means and pole piecesproducing a rotary field and an alternating field; rotors influenced torotate by said fields respectively; and means whereby the rotor in therotating field starts the other rotor. v

7. In combination, a magnet producing an alternating fieldfree-lotrotating field; a rotor influenced to rotate. in and by said field; andmeans influenced by flux of said magnet exterior to said magnet to startthe rotor.

8. In combination, a magnet having one pair of pole pieces; another pairof pole pieces branched ofi from said magnet, said magnet havingexciting means cooperating with said pairs for producing rotary andalternating fields respectively; rotors influenced to rotate by saidfields respectively; and a driving connection between the rotors.

9. In combination, a magnet having one pair of pole pieces; another pairof pole pieces branched off from said magnet, said magnet having ex- 1citing means cooperating with said pairs for producing rotary andalternating fields respectively; and rotors influenced to rotate by saidfields respectively.

10. In combination, a magnet having exciting means and pole piecesproducing an alternating field free of rotating field a rotor in androtated by said field; and means cooperating with and moved by saidmagnet exterior to said magnet for starting said rotor.

' 11. In combination, an exciting means; a magnet excited thereby havingtwo setsof pole pieces, one set producing a rotaryfield, the other. setproducing an alternating field; rotors in and rotated by said fieldsrespectively; and connecting means whereby rotation of one rotor causesrotafield in synchronism therewith; and means intion of the other.

asynchronous rotor having a rapidly revoluble. 12. In combination, amagnet having two'sets.

rotor; and means whereby the synchronous rotor is started by the other.

14. In combination, a magnet having two sets of pole pieces thereon;rotors associated with said sets respectively; exciting means for saidmagnet; said sets, r otors andexciting means being formed to cause onerotor to act as a synchronous rotor and the other as anasynchronousrotor;

and means whereby the synchronous rotor is started by the other.

15. In combination, a stator having exciting windings thereon; two setsof pole pieces on said stator, one set producing a rotary field, theother set producing an alternating field; the same winding exciting bothfields; a rotor in the rotary field and influenced to rotate thereby;and a synchronous rotor in the alternating field and influenced torotate thereby and rotatable by said first named rotor.

16. In combination, a stator having exciting windings thereon; two setsof pole pieces on said stator, one set producing a rotary field, theother set producing an alternating field; the same. winding excitingboth fields; an induction rotor in the rotary field; and a geometricallypolar rotor in the alternating field and constrained to rotate with thefirst named rotor.

1'7. In combination, a magnet having exciting. means and unshaded polepieces producing a pure alternating field free of rotatingfield; a rotorin and rotated by said alternating field in synchronism therewith; andmeans exterior to said alternating field and includingv a part of saidmagnet and operated by said magnet when energized for starting saidrotor. v

18. In combination, a magnet and exciting means therefor producing analternating field; a rotor influenced to rotate in and by said field;and means influenced by the flux of said magnet exterior to said magnetand said alternating field to start the rotor.

19. In a self-starting synchronous motor including a movable memberassociated with the field coil of said motor and movable by the magneticfield when the coil is energized, a rotor synchronously operable by themagnetic field of said coil, and means cooperating with said movablemember to start said rotor at a speed greater than synchronism when saidmember is moved.

20. In combination, a magnet having alternateluding a part of saidmagnet, and excited by said exciting means and adapted on starting toproduce a rotary field to cause the rotor to start. 22. In'combination,a magnet having altemat- 5 ing current exciting means and pole piecesproducing an alternating field normally free of rotating field; a rotornormally rotated by said alternating field; and means including a partof said magnet, and excited, by said exciting means and adapted. onstarting to produce'arotary field to cause the rotor to start. I 1 23.In combination, a magnet having alternating current exciting means andpole pieces producing an alternating field normally free of rotat- 24.In a self-starting synchronous motor m cluding a movable meansassociated with the field coil of said motor and operable by themagnetic field when the coil is energized, a rotor synchronouslyoperable by the magnetic field of said coil, and means cooperating withsaid movable means to start said rotor at a speed greater thansynchronism when said movable means is operated.

25. In a. self-starting synchronous motor in-' eluding a movable memberassociated with the field coil of said motor and rotated by the magneticfield when the coil is energized, a rotor member synchronously operableby the magnetic field of said coil, and means cooperating with saidmovable member to start said rotor member at a ing-field; a rotornormally rotated by said alternating field; and means includinga part ofsaidspeed greater than synchronism when said mov'- able member is moved.

26. In a self-starting synchronous motor including means associated withthe field coil of said motor to provide a rotary field and analternating field, a movable member movable by the rotary field when thecoil is energized, a rotor synchronously operable by the alternatingfield,

, 2'1. In combination, a single magnet having ex-' citing means and polepieces producing a nonrotary alternating field between said "polepieces; a rotor in and rotated by said field between said pole pieces;and means cooperating with, and

moved by, said single magnet exterior to the space between said polepieces for starting said rotor.

' 28. Incombination, a single magnet having exciting means and polepieces producing a nonrotary' alternating field free of rotating field;a rotor in and rotated by said non-rotary field; and means cooperatingwith, and moved by, said magnet exterior to said magnet and saidnon-rotary field for starting said rotor.

29. In combination, a single magnet having exciting means and polepieces producing an' alternating field free of rotating field; a rotorin and Y rotated by said field; and means for starting said rotor,influenced by a part of the flux of said magnet exterior to the spaceadjacent to said rotor.

FRITZ TOEWE.

